Hydraulic power transmitting mechanisms



June 7, 1960 D. W. MOYER HYDRAULIC POWER TRANSMITTING MECHANISMS FiledJuly 22, 1958 15 Sheets-Shea?l l Banald Z Mager PAMQO% June 7, 1960 D.w. MOYER HYDRAULIC POWER TRANSMITTING MECHANISMS Filed July 22, 1958 15Sheets-Sheet 2 15m/fm wzald Zl/.Mo er June 7, 1960 D. w. MOYER 2,939,288

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HYDRAULIC POWER TRANSMITTING MECHANISMS Filed July 22, 195sv June 7,1960 June 7, 1960 D. w. MOYER 2,939,288

HYDRAULIC POWER TRANSMITTING MECHANISMS Filed July 22, 1958 13Sheets-.Sheet 7 June 7, 1960 D. w. MoYER HYDRAULIC POWER TRANSMITTINGMECHANISMS Filed July 22, 195e 13 Sheets-Sheet 8 MIUNHPMUL 7Zala7 ZIJune '7, 1960 D. w. MoYr-:R 2,939,288

HYDRAULIC POWER TRANSMITTING MECHANISMS Filed July 22, 1958 15Sheets-Sheet 9 F 5114 F i E115 Q i l 207 83,. l 19T/wfg@ 97a 27a 87a 201l l/l -l 41a i Jog/ ,f 1111.9, /JQ/a 14g/a l x 14? a' .l 2a

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HYDRAULIC POWER TRANSMITTINC MECHANISMS Filed July 22, 1958 13sheets--smaetI 11 ,aq/.5 50u/w R/Sf Inf/mmf ponad ZW. Mge?" June 7, 1960D. w. MOYER HYDRAULIC POWER THANSMITTING MECHANISMS Filed July 22, 195813 Sheets- Sheet 13 www NN @Nvm United States Patent O HYDRAULIC POWER'I'RANSMITTING 'lVmCI-IANISMS Donald W. Moyer, Chicago, lll., assignerto International Harvester Company, Chicago, Ill., a corporation of NewJersey Filed July zz, 195s, ser. No. 150,200

9 claims. (ci. 60-97) This invention relates to hydraulic powertransmitting mechanisms of the general type wherein a plurality ofenergy-translating devices are operated either individually orsimultaneously, but more particularly it is concerned with a controlvalve adaptable for incorporation into an associated hydraulic systemwherein the operation of one or more uid motors may be controlled atwill.

The invention is somewhat more specifically rleated to manually actuatedcontrol valves so fashioned and constructed that they may be operablyarranged in banks and connected together in a variety of operationalsequences for controlling a plurality of hydraulic motors from a singlesource of fluid pressure, such, for instance, as might be desired in theuse of various types of road construction equipment, farm machinery, orother like applications.

The employment of hydraulic control valves in multple banks hasheretofore been proposed, and, as is well known, many forms of controlvalves adaptable for such use have previously been developed. In thepast it was customary to use separate hydraulic control circuits,including separate pumps, for controlling the operation of varioushydraulic motors associated with the equipment usually operated from avehicle. Generally it was customary, too, to `use one type of hydraulicsystem for the hydraulic motor thatrequired the use of the positioncontrol or follow-up type valve, While another type system was employedfor the hydraulic motors that did not require position control valvestherein. This, of course, necessitated the use of a plurality of fluidpumps in order to provide individual sources of fluid pressure and,since the present trend has been to provide ever increasing amounts ofdifferent kinds of auxiliary hydraulic equipment, the continuedemployment of a separate pump for each individual system will quitenaturally result in bringing aboutv a condition where there will be anexcess number of such pumps and systems carried by the vehicles used forsuch purposes.

An ideal or optimum condition would, of course, seem to suggestcombining the different typ'e systems so as to utilize the best featuresof each while minimizing the drawbacks and disadvantages inherent ineach, and, at the same time, effectively permitting the use of only onesource of fluid pressure. Heretofore, attempts have -been made -toprovide valves that would permit combining different types of systems,but such previous efforts as have been directed thereto have not metwith very favorable acceptance.

M y 2,939,288 ICC Patented June 7, 1960 trols the positioning of thepiston or operating member of an associated liuid motor merely by movingthe control lever of said valve to a preselected position and thenreleasing the lever. It is also quite useful in that such a follow-uptype valve may be used individually or in banks wherein a plurality ofhydraulic devices are controlled thereby. On the other hand, an inherentcharacteristic of the closed-center type of system permits relativelyhigh transient pressures -to develop therein each time the control valveis operated or moved from one of its positions to another, and this, ofcourse, represents an objectionable deterrent to the use thereof forcontrolling certain types of hydraulically actuated devices. Anothercharacteristic of this type system, which may be deemed objectionableunder certain conditions, is that huid under pressure does not flowthrough the control valve itself for use downstream therefrom when saidvalve is in its neutral position. Furthermore, because of the use of apressure regulator means in this type hydraulic system the parasiticlosses may at times be appreciable. Nevertheless, the merits of thissystem commend it for use and, as a result, it has found substantialfavor in the commercial markets for usage that requires positioningcontrol. A control valve together with an associated control systemwhich represents' a modification of the conventional closed-centerhydraulie system, and which hasbeen well received in the industry, isexemplified by the U.S. Patent No. 2,836,195 to Ziskal, issued May 27,1958 which provides a followup control valve of the type adaptable foruse with a pilot regulator or pressure controlling means in a modifiedclosed-center type of hydraulic system. e

When a hydraulic motor to be controlled performs a function that doesnot require positioning control nor the use of a follow-up type ofcontrol valve it has been custmary to employ what is frequently termedinl the art an open-center type system, or one wherein the ilow of lluidpressure through the valve is under the control of the valve itself.This type system is particularly advantageous fbecause it may be usedwithout a pressure regulator and the parasitic losses incident thereto,and, additionally, since the rise and fall of pressures in the systemare so much more gradual the transient pressures which ordinarily occurupon operation of a control valve from one position to another areeliminated, and concomitantly therewith there is provided a smoother andfiner control for the hydraulic system. In this type of system, however,it was not always practicable and easy to operate the control valve inits neutral or float positions with very low by-pass pressures, nor wasit readily feasible to independently operate the individual valves whenarranged in banks because, without the additional parallel type ofcontrol circuits sometimes employed, there was no provision foreffecting the flow of fluid pressure through one valve mechanism to asubsequent Valve when the -iirst valve was in its neutral position.Furthermore, this type system was not readily combined in any well knownindustrial use with the closed-center type of system so as to operateboth systems simultaneously off a single or common source of uidpressure in one installation.

Since the prior art has not heretofore provided a suitable means wherebya hydraulic control system having a pressure regulator therein could besatisfactorily connected to operate from a common source of fluidpressure with a control system that did not contain a pressure regulatortherein, it is a feature of the present invention to overcome theseshortcomings and to provide control valve means so fashioned'as topermit the aforesaid hydraulic systems to be connected together tooperate from a common source of uid pressure, and further ableeitherrindividually or in multiple banks to control one or morehydraulically actuated devices associated therewith.

' A primary objective of the invention, also, is to provide a unique andimproved hydraulic control valve of the type wherein fluidfrom a sourceof uid pressure is .movable throughthe mechanism ofsaid valve toanpendently controlling the operation of a plurality of hydraulicallyactuated devices.

Animportant object is to provide an improved hydraulic control valveadaptable for operation singly or in banks ina hydraulic circuit thatvdoes not utilize a pressure regulator device therein.

Another important object is to provide an improved hydraulic controlvalve of the type wherein one or more of such valves are connectabletogether for parallel voperation in a type of open-center hydraulicsystem, and which system is adaptable for connection in series with oneor more hydraulic control valves incorporated in a type ofYclosed-center hydraulic system, each of said valves being operable toindividually operate an associated hydraulically actuated device, andwherein the combined, systems assembly is operable from a commonsourceof uid pressure,

Arfurther important object is to provide a hydraulic control valve sofashioned that parallel or divided fluid pressure paths are providedtherethrough to permit directing one fluid pressure stream from a sourceon the upstream side of the valve through the controlling mechato permitthe control valves n said systems to be opernism of the valve to anhydraulically actuated device,

t whileY simultaneously another fluid pressure stream isV directedthrough a portion Vof the valve mechanism to another yhydraulic deviceon the downstream side thereof and said latter stream is unaffected whensaid valve is conditioned in its neutral or oat positions.

`Another objectV is provide an improved hydraulic "controlryalve of thetype adaptable for operation singly orin multiple banks in a hydraulicsystem with other control valves of a similarror dissimilar type andwhich improved valvestare so fashioned that each of the valves l in thesystem are individually operable regardless of the operating position ofany-of the other valves therein for ycontrolling the operation of arespectively associated hydraulically actuated device.

The foregoing and other objects and features of the invention willbecome apparent as the disclosure is more fully made in the'followingdetailed description of a preferred embodiment of the invention asillustrated in the accompanying sheets of drawings in which: Y

Figure 1 schematically illustrates Vthe presently proposed species ofhydraulic power transmitting apparatus;

Figure 2 is a front elevational View of a preferred frormrof theimproved control valve incorporated in the' proposed apparatus; Y Figure3 is a top plan of the control valve of Figure 2;

Figure 4 is a vertical sectional View taken on line 4 4 of Figure 3;v 'Yc Figures 5V and 6 are opposite side elevational views of the controlvalve shown in Figure 2, with portions thereof shown broken away toreveal details of construction;

Figure 7 is a horizontal sectional View taken on line 7--7 of Figure 2;Y` Figure 8 isa horizontal sectional view taken on line v8-8 of Figure2; Y

4. "s n A.

Figure 9 is a rear elevational view of the control valve shown in Figure2; l Y

Figure 10 is a'fragmentary horizontal sectional view taken on line 10-10of Figure 9; Y

Figure l1 is a fragmentary horizontal sectional view taken on Vlinel11-11 of Figure A9;

Figure 12 is a-side elevation view of a multiple bank of control v alvesincluding Yan inlet'manifold tower on one end thereof, and havingportions of the side walls ofY said components broken away to showdetails of construction; i u

Figure 13 `is an end elevational view of themultiple bank of controlvalves shown in Figure 12, and having portions thereof broken away toshow constructional details of the components; Y Y

Figure 14 is a vertical sectionalview generally similar to Figure 4 butshowing a modified form of the control valve illustrated in Figure 4; fY

Figure l5 Vis a side elevational view of a modified form of theYcon-trol valve shown inFigurc 14 and depicted with a portion thereofbroken away to reveal details of the components'thereof;

Figure 16 is a schematic view resembling Figure 1 but shown with thecontrol valves thereof in a different scquence of operating positions;V

Figure 17 is a schematic view `of the presently proposed speciesof'hydraulic power transmitting apparatus illustrated in Figure 1, butincluding an additional adapter member disposed between the intermediateand final valve;

Figure 18 is a front elevational view ofthe proposed adapterplate-member;

Figure 19 is an end elevational View of the adapter illustrated inFigure 18; andV Y Figure 20 is a side elevational view, generallysimilar to Figure 12, but showing the incorporation of an adapter platewith a multiple bank of control valves.-

In the accompanying drawings there is'illustrated one preferredembodiment of the invention which has been shown in association with aplurality of hydraulic motors adaptable forY operating Yrespectivehydraulically actuated devices which may take any one of many differentforms but, for purposes of understanding the invention, it was feltfurther specific showings of such devices and the structural detailsthereof was unnecessary;

In Figure 1 there is shown a schematic representation of an hydraulicsystem or power transmitting apparatus incorporating a specicapplicationrof the teachings of the present invention therein, In thisparticular application two hydraulic control valves of a similar typeare connected together in a parallel circuit and this circuit,l

t sented generally by Ythe reference numeral 10, it being understood, ofcourse, that suitable means for driving the said pump will be providedin accordance with standard practice which, generally, takes the form ofthe engine on a vehicle wherein said pump may be mounted.

' YThe outlet of said pump is connected by suitable conduit means 11 anda manifold tower 12, including a safety valve 13, to a first Yhydrauliccontrolrvalve, indicated bythe VreferenceY character 14, whichoperatively controls a vdouble-acting piston 15v in a fluid motor 16connected thereto by conduitsV 17 and 18, while a second hydrauliccontrol valve 14a operatively controls a doubleacting piston 19 in afluid motor 20 connected to said latter valve by conduits 21 and 22, anda third control Ivalve V23 operatively controls a double-acting vpiston24 in a fluid motor 25 connected to said latter valve by con- 'duits'26and 7.7.y The said irst,y second and third valves -are operativelycoupled togetherwithout the use of individual conduits, as will befurther explained as the description proceeds.

The valve 23 is connected by a pressure regulating or control lineconduit 28 and by uid delivering and return conduits 29 and 30,respectively, to a pressure regulator means, indicated generally by thereference numeral 31, while a retrun line conduit 32 empties into areservoir 33 which, in turn, is connected by a conduit 34 to the inletof pump 1G to complete the fluid circuit through the hydraulic systemillustrated.

The valve 23, shown in Figures l, 16 and 17 only in a schematic form, isthe same control valve that is described and claimed in the Ziskal U.S.Patent No. 2,836,195, issued May 27, 1958, but since the structuraldetails of the device are explained at length in that patent, and sincethe operation is the same in both instances, it was felt that repeatingall such details herein would serve no useful purpose. Suiiice it to saythat a valve body casing indicated by the reference 35 is provided toslidably receive a valve spool or plunger 36 that may be moved axiallyby means of an operating arm 37 mounted on a shaft 38 and carrying ashifter fork 39 with a pin 40 therein for engaging a shifter groove 41adjacent one end of said plunger.

A regulating or control passage port 42 in casing 35 is fashioned tocommunicate with the regulator conduit line 28, While reverse llow ports43 and 44 communicate with reverse flow passages 45 and 46 that areconnected, respectively, by conduits 26 and 27 with opposite ends of thecylinder of fluid motor 25. A fluid delivery or pressure port 47communicates with the iluid delivery line 29 and, additionally, with apressure or fluid delivering port of an adjoining valve as will be morefully understood as the description proceeds. The exhaust or return owports 48 and 49 communicate with exhaust passage means 50 formed in thevalve casing and this, in turn, connects with the return ow line orconduit 30.

The valve spool or plunger 36 is fashioned with control port maskinglands 51 and 52 while axially spaced therefrom is a land 53 havingdiametn'cally opposite fluid delivery port masking lands 54 thereon andspaced axially from the latter is a cylindrical land 55. A helicalspring 56 serves to normally maintain the spool of said valve in itscentered or neutral position, While a contracting garter spring 57cooperates with the axially spaced annular shoulders 58 and 59 toprovide detent means for holding said valve spool in various axiallydisplaced operating positions. Y

The pressure controlling or regulating unit 31, shown only in schematicform in Figures l, 16 and 17, is identical with the unit shown anddescribed in the Ziskal U.S. Patent No, 2,83 6,195, while the blockingvalve controlling device portion 60 thereof is further described andclaimed in U.S. Patent No. 2,625,177, and, since further details of thestructural features are contained in these patents, it was feltunnecessary to repeat all of such descriptions herein. The pressure oruid delivery line 29 communicates with a fluid delivery passage 61 inthe regulator which, in turn, communicates with a by-pass passage 62 andwith a passage 63 while the opposite end or port of said uid deliverypassage may be closed with a plug such as indicated at 64. A throttlingorice 65 inpassage Y 63 opens into a control passage 66, and one end orcontrol port of said passage is closed by a plug indicated at 67 whilethe opposite end or control port thereof communicates with regulatorline 28. Exhaust passage means 50, of control valve 23, communicateswith an exhaust passage 68 in the regulator and the opposite end or portof said latter passage is closed by a plug such as indicated at 69.

I'he by-pass passage 62 communicates with one end of an enlarged boreopening 70 which accommodates the stem -71 of a poppet valve head 72constituting a pressure relief or safety valve 73, which head extendsinto a spring chamber 74 formed as an extension of the bore 70. A

6 spring 75 normally urges the valve head 72 into seating relationagainst a narrowed shoulder portion 76, of the bore 70, so as to closeofr communication between the chamber 74 and the by-pass passage 62.Chamber 74 communicates by way of a passage 77 with exhaust passage 68and with a control chamber 78 formed 'as part of the blocking valvecontrolling device indicated at 60. One end of chamber 78 communicateswith control passage 66 while the opposite end of said chambercommunicates with a blocking valve 79 having a chamber 80 therein whichreceives a spring 81 that urges a ball 82 against a ball seat 83 and, inturn, communicates with by-pass passage 62. A plunger 84 having atubular stem 85 thereon is slidably mounted in the control chamber 78and upon movement may engage the ball 82 to displace it from its seat83.

When the valve 23 is in its neutral position, such as shown in Figure 1,the control port masking land 51, of the plunger 36 therein, closes oithe control p ort 42 and iluid in the regulator or control line 28 istrapped and unable to ilow. So long as fluid cannot escape from thecontrol passage 66 the unit pressure on the one end of controllingdevice plunger 84 will be the same as the v unit pressure on the farside of the valve ball 82. Since the area of the one end of plunger 84exceeds the area of ball 82 a unit pressure acting upon the same end ofsaid plunger equal to that acting upon the far side of the ball 82 willprevail over the total force of pressure uid upon the ball 82 and theforce of the spring 81 for unseating the ball 32, even though the unitpressure of the fluid is a nominal pressure at which the iluid isby-passed through the opened blocking valve 79 from the by-pass passage62 to the exhaust passage 68.

So long as the blocking valve 79 is open fluid cannot be delivered bythe pump 10 at a pressure adequate for operating the fluid motor 25.Closing of said blocking valve may be accomplished by allowing fluid toescape from the downstream portion of the passage 63 through either thecontrol passage 66 and line 28, or through the port covered by plug 67,but is best done by moving the Valve 23 from its neutral to eitheroperating position. When fluid is thus allowed to escape from thepassage 63 this drains off uid from the control chamber 78 more rapidlythan iiuid can be supplied through the throttling orice 65 which dividesthe upstream and downstream portions of the control passage 63.Consequently the unit pressure on the one end of the plunger 84 will beless than the unit pressure on the far side of the blocking valve ballS2 whereupon the spring 81 will be effective for closing the blockingvalve 79. With this blocking valve closed fluid pressure then becomesavailable to operate the uid motor 25, as desired, upon actuation of thevalvev In the event of excessive iluid pressure developing in the uiddelivery passage 61 and the by-pass passage 62, this pressure actingupon the outer end of the stem 71 and the end of the head 72 will movethese parts against the pressure of the spring 75 so that the head 72will unseat and allow uid to escape through the pressure relief means 73by way of chamber 74 and passage 77 into the exhaust passage 68 forreturn to the reservoir 33.

Now in accordance with the more specific features hereof the controlvalve that exemplifies the teachings of the present invention, and asshown in Figures 2-12 inclusive, is fashioned with a casing or bodyportion 86 having a cylindrical bore 87 therethrough. A hollowedoutportion at one end of said body provides an end chamber, such asindicated at 88, while at the opposite end co-extensive enlarged boreportions 89 and 90 are provided. A generally cup-shaped cover member 91may be detachably secured to one end of the casing by suitable securingmeans, such as the cap screws 92, While at the opposite end andadjoining chamber 88 said casing is covered with a plate-like coveringmember 93 detachably secured thereto by cap screws 94. The front or Thebore 87 has formed therein and disposed in axially Y spaced relationshiptherealongVv a purality of seven'annular Vrecesses which provideportions of fluid ow passage Vmeans therethrough. One such annularrecess 98, which is slightly spaced from the chamber 86, communicateswith an angularly disposed passage 99 that opens into a work portopening 100 formed in a side face 101 of the body 86. A second annularrecess `103, axially spaced from the rst recess and somewhatbulbous-shaped in plan View (see Figure 1l), communicates with an inletor pressure port opening 104 in the front face 95 and with an alignedoutlet' or fluid delivery port 105 opening in the back face 96 of thecasing. A third annular recess 106 (Figure 8), spaced from the secondrecess 163, communicates by means of a converging and generally flatpassager107 with an-inlet or pressure port 16S opening in the fr ontface 95 of the casing. A fourth annular recess 109 (Figure17), slightlyspaced axially from said third recess, communicates 'by'way ofa'generally flat and converging passage 110 with Van inlet or fluiddelivery port 111 opening inthe back face 96 of the casing. A fifthannular recess 112,V spaced axially from said fourth recess,communicates with a transverse passage 113 (Figure 10), extendingbetween an inlet or pressure port 114 opening in the front face 95 and afluid delivery or outlet port 115 opening in the back face V96 of saidcasing. A sixth .Y annular recess 116, spaced axially from said fifthrecess,

communicates with a generally L-shaped passage 117 that opens into asecond work port 118 opening into the side faceV 101 of said valve body.The seventh annular recess 119,-which is disposedL proximate one end ofthe bore 87 and'axiallyV spaced slightly from said sixth recess,communicates with a passage 120 (Figure 6) that extends longitudinallyof the casing 86 and at its opposite end opens into the chamber S8.V Alateral passage 121 connectsrrthe longitudinal passage 12@ with a returnflow outlet Yport 122 opening in the back face 96 of said casing,

' while the chamber 8S also communicates by way of a y short passage 123with a return ow inlet port 124 opening in the front face 95 of thecasing, the latter port being in general alignment with the port 122 inthe back face 96 thereof.

A counterbore or recess 125 in the back face 96 of said casing (Figure9) is disposed for alignment with one end opening of the regulator orcontrol passage port 42 of valve 23 so that one end of said controlpassage may be closed when certain ones of the adjoining valve faces arevjuxatposed as will be later explained.

A valve spool orrplunger 126, disposed for slidable axial movementwithin the bore `87, is provided with a shifter groove 127 at one endthereof that receives Aa pair of pins128, only one of which is shown,aixed to one end of a shifter Yfork 129 the opposite end of which isxedly mounted on a shaft 13% for rotation therewith. The shaft 130 isjournalled in an opening 131 (Figure 6)` in the front face' 95 of thebody 86 and a liquid seal 132 Vis provided therefor, while the oppositeend of said shaft 139 to prOvide a recess for accommodating theprojecting portion of said arm so that whenfsuch valve ispositionedclosely adjacent another valve there will be no physical interferencewith the operation' thereof.y

The spool or plunger 126'is further fashioned with a plurality of fourlands 140, 141, 142 Yand 143 axially spaced therealong withthe annulargrooves 144, and 146,YV respectively, disposed therebetween. Extendingaxilly inward-ly, from the end of the spool opposite that containing theshifter groove 127, is a recess 147, theV outer end portion of which isprovided with screw threads for threadably receiving a plug-like bearingmember148. An axial opening 149 through said bearing plug is provided toslidably accommodate a bolt 150 the head 151 of which abuts the Yinnersurface of said plug while the shank thereof projects through saidopening and through a pair of generally vcup or bonnet-shaped axiallyspaced brackets 152 and 153 having a coil spring 154 reactively disposedtherebetween. A nut 15SV threadably secured to the end of bolt 150serves as part of an abutment for the bracket153 and thus provides ameans to assistA in limiting axial displacement thereof.

With the valve in neutral the Vspool is centered as shown and thebrackets y152 and 153 are laxially displaced from one another a maximumdistance, with bracket 153 abutting the end cover member 91 whilebracket 152 abuts a shoulder'156` in the enlarged bore portion 90. Whenthe shifter fork `129'is actuated to move the valve plunger upwardly, asviewedV in the drawings, the bearing plug 148 is forced against the head151 of bolt 150 thereby urgingV said bolt to follow the movement of saidplunger and causing the bracket 153 to be moved inwardlyy and tocompressthe spring 154 against bracket 152 which, in turn,is tightly andimmovably pressed against the shoulder 156; hence when the moving orurging force is'removed from the operating arm 13S the compressed spring154 will react to return plunger 126 to its centered or neutralposition. Now when the shifter fork 129 is actuated to urge the plungerdownwardly, as viewed in the drawings, the head and shank of the bolt150 slide further into the axial lrecess 147 while the bearing plug 148pressing against bracket 152 causes it to slide in the enlarged bore 90and to compress the spring 154 and when the operating arm force isremoved said plunger will again return to its centered or'neutralposition.

l In order to provide suitable means for connecting the multiplepressure inlet ports on the front face 95 of valve casing 86 to thesource of fluid pressure there is provided a manifold tower or columnmeans, indicated generally by the reference numeral 12 (Figure 13),which is formed from a head-like member 137 having the reverse or Y,backface 158 (Figure 12) thereof smoothly` finished and flat so as toclosely engage the front face 95 of a valvecasing when positioned,thereagainsa and having a plurality of tie-'bolt openings 159 thereindipsosed for alignment with the respective openings 97 in said valvelcasing so that the bolts, such as 160, may be inserted therethrough tosecure the manifold to the control valve unit. Fluid delivery or outletports 161, 162 and'163 opening in the reverse face of said manifold headare provided with counterbores 164, 165 and 166 each of which is adaptedto receive an O-ring, such as shown at 167 (Figure 12), which provides asuitable liquid seal about each port when aligned with respectivepressure ports in an adjacent valve unit. The ports 161, 162 and 163communicate with an angularly extending passage 168, in the head 157,and this communicates with one end of a transverse passage 169 theopposite end of which opens into a cylindrical chamber 176 extendinginwardly from one edge portion 171 of said head. A coupling 172 suitablymounted inthe open end of chamber serves to connect the inlet conduitY11 from the pump 10 into said'manifold. The inner end of chamber 170communicates by way of a somewhat smaller diameter passageY 173 with asafety valve chamber; 174` aligned with `the chamber 170 and extendinginwardly from another edge portion 175 of the head 157. The safety valvechamber 174 communicates by way of an angularly extending passage 176with a return port 177 opening in the back face 158 of said head, whilea counterbore 178 in said port receives an O-ring, such as shown at 167for port 163, for liquid sealing purposes similarly to the other portstherein. An angularly extending bracket 179 afxed to said head may beused for mountably supporting the said manifold tower and its attachedcontrol valve units on a vehicle or any other structure with which thehydraulic system may be utilized.

Extending into cylindrical chamber 174 and slidably disposed in theinterconnecting passage 173 is a safety or relief valve stem or plunger180 having a split ring 181 on one end thereof that supports saidplunger on the inner edge surface of safety valve chamber 174. Theplunger 4180 is hollowed out to provide an interior axial recess 182 anda plurality of peripherally spaced and staggered openings 183 in thewall of the plunger provide uid communicating means therethrough.Positioned in the chamber 174 is a cup member 184 that receives one endof a coil spring 185 the opposite end of which abuts a cover plate 186aixed over the open end of said chamber by suitable screw means 187. Thespring cup 184 has a portion of the bottom thereof hollowed out, asshown at 188, to accommodate one end of the plunger 180 while apluralityof openings 189 in the bottom of said cup provide fluid communicationmeans therethrough. When the fluid pressure in chamber 170 becomesexcessive it reacts against the interior of axial recess 182, in plunger180, causing the plunger to slide along passage 173 and engage thebottom of spring cup 184 which is thereby moved against the reactiveforce of spring 185. As soon as plunger 180 has moved sufficiently toposition one of the staggered openings 183 therein above the bottom edgeof chamber 174 fluid becomes free -to escape through said opening intothe hollowed out portion 188 in the cup 184 and then through theopenings 189 therein into the safety valve chamber 17 4, which, being incommunication with the return fluid passage 176, relieves the excessivepressure in the system. A further rise in pressure would, of course,cause greater compression of the spring 185 and thus permit even greaterrelief of pressure in chamber 174 by way of return passage 176. When thepressure subsides to normal the spring 185 will react to restore thesafety Valve, indicated generally by the reference numeral 190, to itsoriginal position, in which there is substantially no interchange of uidbetween the cylindrical chamber 170 and the relief valve chamber 174.

'Ihe uid delivery ports 105, 111 and 115 and the return ow port 122 onthe reverse or back face of the valve casing 86 are each formed with acounterbore, such as shown at 191, 192, 193 and 194, that is adapted toaccommodate an O-ring type of liquid seal, such as indicated at 195(Figure 12). When it is desired to use two or more of such valve unitsin a multiple or banked relation, the reverse or back face of the rstValve is positioned against the smooth obverse or front face side of thenext succeeding valve with the fluid delivery outlet ports of theupstream valve in register with the pressure inlet ports of thedownstream valve, and with the individual O-ring seals providingsuitable uid seal means between the respectively aligned ports, whilethe long-shank tiebolts 160 function to tightly couple the valvestogether in a liquid tight relationship. The counterbore 125. in thereverse face of valve casing 86 is disposed in alignment with thecontrol or regulator passage port 42 of valve 23. As fashioned thiscontrol passage extends from front to back through the body of valve 23and the control conduit line 28 communicates with a portion of thepassage other than the ends thereof as would appear from the schematicrepresentation of Figures 1, 16 and 17, while the port ends of saidpassage are in communication with adjoining valves. Since the adjoiningvalve in this instance is of the type that does not require theregulator or control featurefor its operation, the adjoining portpassage may be closed by an O-ring disposed in the respectiveregistering counterbore,

When a modified type of open-center valve, such as is illustrated by thereference numerals 14 or 14a, is coupled for operation to a modied typeof closed-center valve, of the type schematically represented by thereference numeral 23 in Figures l, 16 and 17, only one of the uiddelivery outlet ports of the open-center type valve is connected to apressure inlet port of the closed-center type valve 23 and the unusedports are sealed olf by O-rings, such as illustrated at 195 or 19511(Figure l2), disposed in abutting relation with the blank Wall of thelatter valve unit. In the event the proposed valve is to be employedindividually without other control Valves in the downstream side of anhydraulic system, none of the luid delivery outlet ports ordinarily usedfor delivery of fluid to subsequent valves need be used to deliver fluidand hence all such ports may be sealed-olf by suitable coverplate means,such, for instance, as the cover-plate indicated at 196 for covering thereverse face of the nal valve in the series. t

In Figures 14 and l5 there is depicted a modified form of the proposedimproved valve while Figures 1, 16 and 17 schematically illustrate theemployment of the modi-v ed valve in a combination hydraulic system. Forpurposes of-V simplicity, like elements have been designated with thesame reference characters, plus the addition of the suffix a thereto, aswas used in describing the rst preferred form of the improved valveunit.

The modified valve unit is designed to provide an additional valveoperating position, that of oat, whereby the piston of the uid motorassociated therewith is iloatably movable without operating the valvespool mechanism. Such a position is desirable, as is well understood,for certain types of hydraulically actuated equipment but may beobjectionable in other instances, hence the proposed valve of thepresent invention is constructed so as to be readily adaptable forchanging from one form to the other with a minimum of effort andexpense.

In'its modified form the valve unit comprises a casing 86a having acylindrical bore 87a and a hollow chamber 88a at one end, and enlargedbores 89a and 90a at the opposite end. A cup-shaped cover 91a isdetachably afxed at one end by the screws 92a, and the opposite end iscovered with a plate-like member 93a having an opening 197 therein andis secured by screws 94a, while an additional protective bonnet member198 is secured over the .opening 197 to said cover-plate by the screwsindicated at 199. The front face 95a and back face 96a of said casingare smoothly finished and disposed parallel to one another, while aplurality of openings 97a provide for receiving suitable fasteningbolts.

The bore 87a has, as in the first preferred form of the valve, sevenannular recesses, the first of which indicated 98a, communicates by wayof passage 99a with the work port 10M, the second recess, indicated103a, communicates with inlet port 10411 and aligned outlet port a, thethird recess 106:1 communicates with inlet port 108a, the fourth recess109a communicates with outlet port 15mn, the fifth recess 112ercommunicates with the inlet port 114e and outlet port 11511, the sixthrecess 116g communicates by way of passage 117a with work port 11811,and the seventh recess 1=19a communicates by way of passages 120:1 and121a with the end chamber 88a and with return flow outlet port 122e,respectively, and by way of passage 123g with the return flow inlet port124:1.

A valve spool or plunger 1`26a has a shifter groove 127a on one endthereof that receives a pin 128a aixed i, ventionf t Y t'shifter fork'129111,-jn1tur-n; mounted'on shaft '13011; Shaft 13,911 is'journalledinopening 13111 and .iitted with liquid seal 13211; and a Y'reducedsection portion 133a on said shaft .is mounted by a pin 13411 in bearingmember 13511 journalled in openingxlorr and provided with a conventionalliquid seal 13711 therearound. An operating arm 13811 on shaftf139c1-extends outwardly beyond the front face of the casing, while thereverse face 9611 of said casinghas a cutaway or recessed portion'139athere-A in for accomodating the operating armrextension of an adiacentlydisposed valve.

The spool A12611 is fashioned with lands 14051, 14161, 14211 and 14311having annular grooves 14411, 14511 and 14511 therebetween, while anaxial recess 14711 therein threadablyV receives a plug-like bearingmember 14811 having an opening 14911 therethrough which slidablyaccommodates the shank of a bolt 15611 the head 15111 of which abutstheV innerV surface of saidV bearing member. The shank of said boltprojects through a generally cup or bonnet-shaped bracket'15311 andthrough a washer-like disc or'thrust plate member 241i) as well asthrough a coil yspring 154:1 reactively disposed between said bracketand disc.VVV A nut 15511 threadably secured to the end of boltla servesto position the bracket 153:1, while the disc 260 abuts a shoulder 15611in therenlarged bore 91111.

The opposite end of spool 12511 has an axial recess 291 therein thatis`threaded tofreceive an extension spool Y 262 which is slidable throughopening-197 in coverplate 9311 and which extends therebeyond intowthebonnet'cover 193. AXially spacedA annualil grooves 293 and 2.514 insaidextensionvmemberrareadapted to .cooperate with a contracting'garterspring 21,15, disposed infan annular` goove'Z--in aplate. cover 9311,1toprovide detent means for holdingthe valve spoolin certain axiallydisplaced positions( thereof. Groove `203,V for instance, Y ispositioned tore'ceive garter spring 205 when the valve is conditionedfor lowering the tluid motor piston associated therewith, while groove264 Aaccommodates said spring when the valve is movedttoitsfloatfposition. It will be appreciated, ofY course, that Y'additionaldetent means such as the groovetshown at-207- may ben provided for otherpositions of the valve, if desired, without deviating from any of theteachings ofthe present in- 1n Figurel7 there is schematicallyrepresented acombined hydraulic system, generally similar Ato the oneshown in Figures l and 16, but wherein additional fluid delivery passagemeans have. been provided between the Y linal open-center type valve andthe rst'valverof. the

closed-center type in the systerrr, An interchange bridge orinterconnectingadapter plate, indicatedat 268 (Figures `17-20), isfashioned from aihead member 2119 having the front` and reverse faces210 and 211 thereof smoothly iinished and parallel to one another, andhaving Va plurality of peripherally spaced openings, suchV as 212,extending between said faces. A through passage 213 with a port 21d inthe front face anda port 215 in the back face has a counterbore216Awh1ich 'is adapted t' to receive an O-ring 217 (Figure 20) therein.A luidY delivery Vor inlet port 218 in the front face 219 communicatesby way of -a passage 219 with aV similar inlet portV 229 opening in saidfront face, and by way of passage 221 with an outlet port 222 opening inthe reverse face,

Ytie-bolts 161 which serve to tieall the valve units in the assemblytogether.

12 oPERAnoN I Vinrorder to/best understand the operation of Vtheproposed invention reference is had Vtothe schematic diagram of Figurel, wherein three hydraulic control valves are illustrated as arrangedfor a banked operation with each valve shown conditioned for Vadin-ferent operating position, such positions having been set by therespective operatingmechanisms thereof. Y

' Fluid pressure from thek hydraulic pump 10 is directed by way ofconduit 11 to the manifold tower 12 thence into the inlet ports 1%4, 108and 114 of the rst valve (14. With the initial valvelt in position forraising or lifting its associated hydraulc motor 1o the spool lthereofwill be Vpositioned as indicated and fluid is then free to ow from port'11?4 around groove 144 and out work port 100 into conduit 157 andagainst the liftingY surface ofpiston 15 in the hydraulicrmotor or ram16,' while the opposite side ofV said piston, being connected byconduit. 18to the Ywork port 113, communicates by way of recess 119 andpassage 121) with the return fluid chamber 'SS of the valve. Thus, asthe piston 15, in hydraulic motor 16,'is raisedV the iiuid exhaustedtherefrom' is directed back Vto the return circuit and, byrway of returnport 122, into the next valve in the system. At the same time luid underpressure passes from Huid d'e'liveryport J115, 'of valve 14, to'pressureport 113511 Yof the "adjoining valve 14a, 'where itn is-vlai'failablefor use as required, and fluid passing through port 104, annular 'recess144 and portY 1115' o said initial Ivalve'is delivered into port 16411of the adjoining valve 12111.A i Y t Furthermore, when Vthe spool V126ofrs't valve 14 is moved so"thatthis "valve becomes conditioned forloweringthe piston of its associated ram unit the spool will bepositioned for 'directing fluid pressure from port'104 around groove2144 and through port 105 into the respective port 10411 of the adjacentvalve/whileV uid pressure entering inlet port 114 is directedv by wayof'outlet port 11S into the respective inlet port 1141101? said adjacentvalve so that tluid pressurey is then *available at ports 10411 and11411 for use upon operation of said latter valve. Thus, it will beappreciated that the fluid pressure enteringtheinitial Valve V1li isavailable for raising or lowering the iluid motor 16 associated there-ywith and Ysimultaneously for providing fluid pressure at ports 10411,fla'and V11311 of the adjoining valve for use in' operation of the fluidymotorV 20 vassociated with said latter valve.

With the second'valve 14a in the system conditioned for its lowering ordropping operation the Yspool therein will'be positioned as indicatedin'Figure l and Ythe Yiluid opposite side of piston 179 communicates byway of conduit 21 with port 'Nida lthe tiuid on that sideof the pistonis free kto passthrough said conduit into said latter port and thencepast the land 14011 and into the returnmow end chamberSSa whichcommunicates by way lof port 12211 withrthe corresponding return flowport of the next adjoiningV downstreamv valve and from there through thedischarge meansrSt) to return line V30 that, in turn, empties by wayY ofline 32 finto reservoii-SS which, of course, is connected by way ofrconduit 34 with the inlet of pump 16. Since uid pressure isalsosimultaneously available-at ports 111411 and 1t3a in said second valvethe' spool 12611'thereof may be shifted to its Vraising or liftingposition whereupon 'pressure .would .then be available for passagethrough port 10011 and conduit 21 into theraising'side of fluid motor2G. Thus, it will be seen that this second valve may be operated forraising and lowering while the irst or preceding vaivejisrfin either itsraising -or `lowering positions. It will be noted, however, Vthattherecis n ouid pressure available at port L17in 13 the third orsucceeding valve 23 during these operations, hence this last valvecannot be operated to actuate an associated hydraulic device when eitherof the preceding valves 14 -and 14:1 are in their raising or loweringoperating positions.

In Figure 16 there is a schematic showing of a hydraulic system,generally similar to the one shown in Figure 1, but having the controlvalves shown conditioned for dilerent operating sequences. In thisinstance the first valve 14 is in neutral, and the second valve 1411 isin oat position, while the nal valve 23 is in its raising or liftingposition. When the first valve 14 is in neutral uid is trapped againstmovement in the conduits 17 and 18 and the piston 15 of uid motor 16 ismaintained in a hold position. Fluid pressure now entering inlet port168 in said valve passes around groove 14S and out through port 111 intoinlet port 198:1 of

the immediately adjoining valve 14:1. With the second valve `14:1 in itsoa-t position, such as is indicated in Figure 16, uid pressure receivedat port 108:1 thereof is directed by way of groove 144:1 into port 111:1which communicates with the inlet port 47 of the next adjoining valve 23and with the pressure line 29. With valve 14:1 in the float position theraising side of piston 19, of uid motor 20, freely communicates by wayof conduit 21 and port 100:1 with the return ow end chamber 88:1, whilethe lowering side of said piston freely communicates by way of conduit22 and ports 118:1 and 119:1 also with the return ow chamber 88:1, andsince said latter ports and the return ilow chamber are interconnectedby the passage 120:1 the piston is tree to iioat within the cylinder ofsaid fluid motor. Now, since pressure is available at the port 47 of uidvalve 23 when such last valve in the system is moved to its lifting orraising position iiuid pressure will pass by way of passage 46 outthrough port 44 into conduit 26 and into the raising side of piston 24of the uid motor or ram unit 25 associated therewith, while the loweringside or said piston, whichconnects with conduit 27, relieves thepressure therewithin by directing fluid through said conduit and port 43into the passage 45 which communicates by way of port 49 with theexhaust passage means 50 and return conduit line 30. Thus, so long asuid pressure is available at port 47 the valve 23 may be operated, aspreviously described, from one position to another for actuating theiluid motor 25 associated therewith. As previously outlined, fluidpressure is available at this port normally only when the rst valve isin neutral and the second valve is either in a neutral or a iioatposition.

In the 'schematic diagram represented by Figure 17 the proposedhydraulic system is shown as incorporating therein an adapter connector208 which provides additional passage means whereby the final valve unitin the proposed system becomes operable for actuating its associatediluid motor regardless of the operating positions of any of thepreceding valves in said system. For purposes of illustrating thispossibility the middle valve 14:1 is shown (in Figure 17) in itslowering or dropping position'whereupon uid pressure received therein byway of port 104:1 is directed through outlet port 105:1 and inlet port218 into passage 219 of the adapter 283 thence by way of port 222 insm'd adapter into the pressure port 47 of nal valve 23 where said fluidpressure becomes available for use by the latter valve for actuating itsassociated uid motor 25. At the same time iluid under pressure deliveredto middle valve 14:1 by way of inlet port 114:1 is divided and a portionthereof is passed by way of outlet port 115:1 and inlet port 220 intopassage 222 of said adapter, while the balance is directed by way ofwork port 118:1 and conduit 22 into the lowering side of the fluid motoror ram unit 20. Hence, it will -be appreciated that so long as uidpressure is availthe nal valve 23 for use upon opera-tion of said lattervalve. When middle valve l14:1 is conditioned for raising, for example,the spool therein will then be disposed so that uid under pressuredelivered at port `104:1 is divided with part going into conduit 21 forraising fluid motor 19 and the remainder going by way of ports 15a and218 into passage 219 of the adapter connector 208. At the same time uidunder pressure delivered to port 114:1 of said middle valve is directedby way of port 115:1 into the passage 219 of said adapter. Thus,regardless of the operated position of middle valve 14a fluid pressurewill be available at port 47 in nal valve 23 for use in connection withthe operation thereof for -actuating an associated hydraulic device.

Variants in structurevof individual components of the system disclosedwill readily .occur to skilled designers in the field. Accordingly, eventhough particular em- A bodiments and applications of the invent-ionhave been able at either port 105:1 or 115:1 of the intermediate valve14:1 there will be pressure available at inlet port 47 of shown anddescribed in some detail, there is no intention to thereby limit theinvention to such speciiic forms or Vthe particular employments hereindicated. On the contrary, the intention is to cover all modificationsand alternative arrangements falling within the spirit and scope of thepresent invention as expressed in the appended claims.

What is claimed is;

1. A hydraulic power transmitting apparatus comprising, Vin combination:a, single source of uid pressure; a trst hydraulic control valve unithaving a 'plurality of inlet and outlet Aports therein and connectedthrough certain of said inlet ports with said source of fluid pressure;a hydraulic motor `connected to certain of said outlet ports of said rstvalve and actuable upon operation of said first valve; a secondhydraulic valve of the type having a plurality of fluid accommodatingports and adapted for positioning control of an associated hydraulicallyactuated device; a second hydraulic motor connected to said second valveand actuable upon operation of said second valve; pressure regulatingmeans interconnected between said second valve and said source of iluidpressure; one of the ports of said second valve being disposed in fluidpressure communication relation with a certain outlet port of said rstvalve, said certain outlet port being simultaneously in fluid pressurecommunication relation with said pressure regulator whereby tluidpressure may be transmitted therebetween; said first valve including avalve body having a bore therein :and a spool -slidably disposed withinsaid bore, and fluid passage means formed in said body and cooperativewith said spool for interconnecting certain of said ports to establishfluid pressure communication therebetween and from the said sourcethrough said ports to said associated hydraulic motor, said spool beingslidable axially within said bore whereby said spool is positioned inany one of a plurality of axially displaced positions during two ofwhich positions iluid pressure communication is established by Way ofsaid passage means lbetween the said source and said associatedhydraulic motor to effect the operation of said motor whilesimultaneously fluid pressure communication from said source throughsaid iirst valve to said second valve is interrupted, and during anotherof said axially displaced positions of the spool fluid pressurecommunication to said associated hydraulic motor is interrupted whilesimultaneously lfluid pressure communication is established from thesource through said rst valve by way of said passage means to saidsecond valve and to said pressure regulator.

2. A hydraulic power transmitting apparatus comprising, in combination:a .single source of fluid pressure; a rst hydraulic control valve unithaving a plurality of inlet and outlet portsY therein and connectedthrough certain of said inlet ports with said source of uid pressure; ahydraulic motor connected to certain of said outlet ports of said rstvalve andactuable upon operation of said first valve; a second hydraulicvalve of the type

